Tumor necrosis factor-alpha (TNFalpha) regulates the epithelial barrier in the human intestinal cell line HT-29/B6

Cytokines are supposed to be mediators in diarrhoeal diseases. The aim of this study is to characterize the effect of tumor necrosis factor-alpha (TNFalpha) on epithelial barrier function in the colonic epithelial cell line HT-29/B6. Active ion transport and barrier function were measured as short-circuit current and transepithelial electrical resistance (Rt), respectively. In parallel, freeze-fracture electron microscopy (EM) of tight junctions (TJ) and immunofluorescence microscopy of the zonula occludens protein-1 (ZO-1) were performed. Serosal addition of TNF(alpha) (100 ng/ml) decreased Rt by 81%. This effect was dose-dependent and could be mimicked by antibodies against the p55 form of the TNF receptor. Cytotoxic effects were excluded by a negative lactate dehydrogenase (LDH) assay. Immunofluorescence localization with anti-ZO-1 antibodies revealed no evidence for disruption of the monolayer after TNFalpha treatment. In freeze-fracture EM, TJ complexity was decreased by TNFalpha, as indicated by a decrease in the number of strands from 4.7 to 3.4. The tyrosine kinase blocker genistein and the protein kinase A inhibitor H-8 reduced the effect of TNFalpha. A combination of TNFalpha with interferon-gamma acted synergistically on the epithelial barrier. In conclusion, TNFalpha impairs epithelial barrier function by altering structure and function of the tight junction, which could be of pathogenic relevance in intestinal inflammation.

Mucosal but not peripheral FOXP3+ regulatory T cells are highly increased in untreated HIV infection and normalize after suppressive HAART

Recent evidence indicates that regulatory T cells (T(regs)) play an important role in HIV infection. However, although the gastrointestinal mucosa is a key compartment in HIV disease, no data on mucosal T(regs) in HIV infection are available. In this study, we compared the frequency of T(regs) in duodenal mucosa and peripheral blood (PB) of 13 treatment-naive and 13 suppressively treated HIV-infected patients with that of 6 patients with norovirus infection and 12 healthy controls. T(regs) were quantified by immunohistochemistry (CD3/FOXP3) and further characterized (CD25, CTLA-4, GITR) by immunohistochemistry, immunofluorescence, and fluorescence-activated cell sorting (FACS). Both the frequency and the absolute count of mucosal T(regs) were highly increased in untreated HIV patients but were normal in treated HIV patients. In contrast, in peripheral blood of HIV patients, the absolute number of T(regs) was not increased, and their frequency was only slightly elevated. In norovirus infection, frequency of mucosal T(regs) in the CD4+ T-cell subset was not elevated. The high increase in count and frequency of mucosal T(regs) seems to be a characteristic feature of untreated HIV infection, suggesting a significant contribution of T(regs) to the pathogenesis of HIV disease. Their role may be 2-edged: attenuating HIV-induced immune hyperactivation while suppressing the immune response to HIV and mucosal pathogens.

Cytokine-dependent transcriptional down-regulation of epithelial sodium channel in ulcerative colitis

BACKGROUND & AIMS

The main limiting factor for sodium absorption in distal colon is the amiloride-sensitive epithelial sodium channel (ENaC). This study aimed to characterize mechanisms involved in the dysregulation of ENaC expression in ulcerative colitis (UC).

METHODS

Epithelial preparations from surgically removed inflamed and control sigmoid colons were used. Active electrogenic Na(+) transport (J(Na)) was determined after 8-hour aldosterone stimulation in Ussing-chambers (corrected for the altered epithelial/subepithelial resistance ratio). Subsequently, ENaC alpha-, beta-, and gamma-subunits were analyzed immunohistochemically and in Western and Northern blots (corrected for the inflammatory increase in subepithelial protein content). To study gene regulation, the promoters of beta- and gamma-ENaC were analyzed in reporter gene assays.

RESULTS

In controls, aldosterone stimulated J(Na) and induced ENaC beta- and gamma-subunit expression, whereas this response was virtually abolished in UC. Preservation of surface epithelium in UC was indicated by unchanged ENaC alpha-subunit expression, which points also against a mere immaturity or epithelial cell loss. Inhibition of electrogenic sodium transport as well as beta- and gamma-ENaC mRNA expression could be mimicked in control colon by in vitro preexposure for 8 hours to tumor necrosis factor alpha and interferon gamma. Promoter analysis revealed that down-regulation of beta- and gamma-ENaC gene expression was primarily induced by tumor necrosis factor alpha.

CONCLUSIONS

We conclude that, in UC, elevated proinflammatory cytokines selectively impair beta- and gamma-ENaC expression, which contributes to diarrhea by reducing colonic sodium absorption.

Correlation of T cell response and bacterial clearance in human volunteers challenged with Helicobacter pylori revealed by randomised controlled vaccination with Ty21a-based Salmonella vaccines

BACKGROUND

Helicobacter pylori remains a global health hazard, and vaccination would be ideal for its control. Natural infection appears not to induce protective immunity. Thus, the feasibility of a vaccine for humans is doubtful.

METHODS

In two prospective, randomised, double-blind, controlled studies (Paul Ehrlich Institute application nos 0802/02 and 1097/01), live vaccines against H pylori were tested in human volunteers seronegative for, and without evidence of, active H pylori infection. Volunteers (n = 58) were immunised orally with Salmonella enterica serovar Typhi Ty21a expressing H pylori urease or HP0231, or solely with Ty21a, and then challenged with 2x10(5) cagPAI(-) H pylori. Adverse events, infection, humoral, cellular and mucosal immune response were monitored. Gastric biopsies were taken before and after vaccination, and postchallenge. Infection was terminated with antibiotics.

RESULTS

Vaccines were well tolerated. Challenge infection induced transient, mild to moderate dyspeptic symptoms, and histological and transcriptional changes in the mucosa known from chronic infection. Vaccines did not show satisfactory protection. However, 13 of 58 volunteers, 8 vaccinees and 5 controls, became breath test negative and either cleared H pylori (5/13) completely or reduced the H pylori burden (8/13). H pylori-specific T helper cells were detected in 9 of these 13 (69%), but only in 6 of 45 (13%) breath test-positive volunteers (p = 0.0002; Fisher exact test). T cells were either vaccine induced or pre-existing, depending on the volunteer.

CONCLUSION

Challenge infection offers a controlled model for vaccine testing. Importantly, it revealed evidence for T cell-mediated immunity against H pylori infection in humans.

Acute HIV infection induces mucosal infiltration with CD4+ and CD8+ T cells, epithelial apoptosis, and a mucosal barrier defect

BACKGROUND & AIMS

A barrier defect of the intestinal mucosa is thought to affect the progression of human immunodeficiency virus (HIV) infection. It is not clear whether the mucosal barrier impairment already is present in acute infection and what mechanisms cause this defect. We analyzed T-cell subsets, epithelial apoptosis, and barrier function of the duodenal mucosa in patients with acute HIV infection.

METHODS

Mucosal T-cell subsets, epithelial apoptosis, and barrier function were assessed by immunohistochemistry, immunofluorescence, flow cytometry, and impedance spectroscopy in duodenal samples from 8 patients with early acute infection, 8 patients with chronic infection, and 9 HIV-negative individuals (controls). One patient was analyzed serially, before and during acute infection.

RESULTS

Compared with controls, densities of mucosal CD8+ and, surprisingly, of mucosal CD4+ T cells too, increased in patients with acute infection. Most mucosal CD4+ T cells had an activated effector memory phenotype (CD45RA-CD45RO+CD62L-CD40L+CD38+) and did not proliferate. Perforin-expressing mucosal CD8+ T cells also were increased in acutely infected patients; their frequency correlated with epithelial apoptosis. The epithelial barrier was impaired significantly in patients with acute HIV infection. The patient analyzed serially developed increased densities of mucosal CD4+ and CD8+ T cells, increased apoptosis of epithelial cells, and mucosal barrier impairment during acute infection.

CONCLUSIONS

Before depleting CD4+ T cells, acute HIV infection induces infiltration of the mucosa with activated effector memory CD4+ and CD8+ T cells. The HIV-induced barrier defect of the intestinal mucosa is evident already in acute infection; it might arise from increased epithelial apoptosis, induced by perforin-positive mucosal cytotoxic T cells.

13C-urea breath test in Helicobacter pylori diagnosis and eradication. Correlation to histology, origin of 'false' results, and influence of food intake

BACKGROUND

Which protocol is optimal for the 13C-urea breath test (UBT) for Helicobacter pylori detection is controversial. This study aimed to characterize a very simple UBT protocol for the clinical routine (two-point-analysis performed with 75 mg 13C-urea and citric acid) with special consideration of 'false' UBT results. RESULTS; UBT was evaluated in reference to histology (Warthin-Starry). In mismatching results re-gastroscopy was performed. By UBT, 74 of 77 patients with H. pylori-positive histology were detected (sensitivity, 96%). The false-negative UBTs were due to low colonization densities during spontaneous H. pylori elimination or pyloric obstruction. Seven of 49 patients with negative histology had a positive UBT, but re-gastroscopy showed that all of them had a positive histology when multiple antral biopsy specimens were taken (UBT specificity, 100%). UBT correlated only weakly with H. pylori colonization density. No correlation was found between UBT and gastric neutrophil and lymphocyte infiltration. UBT reproducibility was excellent (93 of 94 in a 6-month period). Non-fasting conditions induced a shift to lower UBT results in H. pylori-positive and to higher UBT results in negative patients, resulting in 2 of 10 false-positive and 1 of 10 false-negative UBTs.

CONCLUSION

This simple version of the urea breath test combines the highest sensitivity with excellent reproducibility. It is superior to histologic detection of H. pylori in the clinical routine and an optimal tool for monitoring H. pylori eradication. Fasting conditions are required for the test.

Macrophages accumulate in the gut mucosa of untreated HIV-infected patients

BACKGROUND

Mucosal macrophages are involved in the maintenance of epithelial barrier integrity and the elimination of invading pathogens. Although an intestinal barrier defect and microbial translocation are hallmarks of human immunodeficiency virus (HIV) infection, recent data on gut mucosal macrophages in HIV infection are sparse.

METHODS

Treatment-naive and treated HIV-infected patients and healthy controls were studied for frequencies and functional parameters of blood monocytes and macrophages in duodenal mucosa.

RESULTS

We found mucosal enrichment of macrophages in untreated HIV infection associated with reduced monocyte counts in blood and increased monocyte expression of the gut-homing molecule integrin β7. Increased CCR2 density on integrin β7-expressing monocytes and mucosal secretion of CCL2 suggest that CCR2/CCL2-chemotaxis is involved in enhanced trafficking of blood monocytes to the gut. Secretion of macrophage-related proinflammatory molecules interleukin 1β, CCL5, CXCL9, and CXCL10 was increased in the gut mucosa of untreated patients. Moreover, mucosal macrophages of untreated patients showed reduced phagocytic activity.

CONCLUSIONS

These data suggest a role for gut mucosal macrophages in HIV immune pathogenesis: infiltrated macrophages in the intestinal mucosa may promote local inflammation and tissue injury, whereas their low phagocytic activity prevents the efficient elimination of luminal antigens that cross the damaged intestinal barrier.

Early aldosterone effect in distal colon by transcriptional regulation of ENaC subunits

Aldosterone-induced sodium absorption is mediated by the epithelial Na(+) channel (ENaC). It is thought that the "early effect" is not based on genomic regulation of ENaC expression, because ENaC subunit transcription was reported to start later than Na(+) transport. We investigated electrogenic Na(+) absorption (J(Na)) and, in identical tissues, mRNA expression of ENaC subunits in early (EDC) and late (LDC) distal colon of the rat. In both segments, 8-h in vitro incubation with 3 nM aldosterone enhanced expression of beta- and gamma-ENaC mRNA and induced J(Na). J(Na) was 10 times higher in LDC than in EDC. alpha-ENaC mRNA was unchanged in EDC, whereas it decreased in LDC. In LDC, beta- and gamma-ENaC mRNA was induced 1 h after aldosterone addition, whereas J(Na) became apparent >1 h later. Downregulation of alpha-ENaC mRNA did not take part in acute regulation because it started after a lag time of 3 h. Time correlation of beta- and gamma-ENaC induction and J(Na) stimulation suggests that the early aldosterone effect on Na(+) absorption in distal colon is caused by transcriptional upregulation of beta- and gamma-ENaC expression.

Differential stimulation of intestinal mucin secretion by cholera toxin and carbachol

Cholinergic stimulation triggers the secretion of apically stored, preformed mucin from goblet cells but the pathway of cAMP-stimulated mucin secretion is not known. In this study the effect of cholera toxin on mucin secretion in the human colonic goblet cell line HT-29/B6 was investigated and compared to the action of carbachol. PAS staining of mucin blotted onto nitrocellulose served to quantify the secretion of total mucin. Metabolic labelling was used to evaluate the secretion of newly synthesized mucin. The mucinous nature of the detected material was confirmed with an immunoblot employing a well-characterized polyclonal antibody reacting with MUC2-mucin. Cholera toxin caused a 116-fold increase of intracellular cAMP and strongly stimulated the secretion of both preformed and newly synthesized mucin for more than 20 h. Carbachol only triggered the release of preformed mucin immediately after addition. The secretory response to cholera toxin could be partly inhibited by the protein kinase A inhibitor H8 and the microtubule inhibitor colchicine. The action of carbachol was not affected by these agents. In conclusion, we demonstrate a direct cAMP-dependent effect of cholera toxin on mucin secretion by intestinal goblet cells. In contrast to carbachol, the action of cholera toxin involves de novo synthesis of mucin molecules and microtubule-mediated secretion. There seem to be distinct secretion pathways for muscarinic or cAMP-dependent stimulation of mucin secretion.

Escherichia coli alpha-haemolysin induces focal leaks in colonic epithelium: a novel mechanism of bacterial translocation

Extraintestinal pathogenic Escherichia coli (ExPEC) are usually harmless colonizer of the intestinal microflora. However, they are capable to translocate and cause life-threatening disease. Translocation of ExPEC isolates was quantified in colonic monolayers. Transepithelial resistance (R(t)) was monitored and local changes in conductivity analysed with conductance scanning. Confocal microscopy visualized the translocation route. Corroboratory experiments were performed on native rat colon. One translocating strain E. coli O4 was identified. This translocation process was associated with an R(t) decrease (36 +/- 1% of initial resistance) beginning only 2 h after inoculation. The sites of translocation were small defects in epithelial integrity (focal leaks) exhibiting highly increased local ion permeability. Translocation was enhanced by preincubation of monolayers with tumour necrosis factor-alpha or interleukin-13. Mutant strains lacking alpha-haemolysin lost the ability to induce focal leaks, while this effect could be restored by re-introducing the haemolysin determinant. Filtrate of a laboratory strain carrying the alpha-haemolysin operon was sufficient for focal leak induction. In native rat colon, E. coli O4 decreased R(t) and immunohistology demonstrated focal leaks resembling those in cell monolayers. E. coli alpha-haemolysin is able to induce focal leaks in colonic cell cultures as well as in native colon. This process represents a novel route of bacterial translocation facilitated by pro-inflammatory cytokines.

PuraStat in gastrointestinal bleeding: results of a prospective multicentre observational pilot study

Background

A recently developed haemostatic peptide gel for endoscopic application has been introduced to improve the management of gastrointestinal bleeding. The aim of this pilot study was to evaluate the feasibility, safety, efficacy and indication profiles of PuraStat in a clinical setting.

Methods

In this prospective observational multicentre pilot study, patients with acute non-variceal gastrointestinal bleeding (upper and lower) were included. Primary and secondary application of PuraStat was evaluated. Haemoglobin, prothrombin time, platelets and transfusion behaviour were documented before and after haemostasis. The efficacy of PuraStat was assessed during the procedure, at 3 days and 1 week after application.

Results

111 patients with acute gastrointestinal bleeding were recruited into the study. 70 percent (78/111) of the patients had upper gastrointestinal bleeding and 30% (33/111) had lower gastrointestinal bleeding. After primary application of PuraStat, initial haemostatic success was achieved in 94% of patients (74/79, 95% CI 88–99%), and in 75% of the patients when used as a secondary haemostatic product, following failure of established techniques (24/32, 95% CI 59–91%). The therapeutic success rates (absence of rebleeding) after 3 and 7 days were 91% and 87% after primary use, and 87% and 81% in all study patients. Overall rebleeding rate at 30 day follow-up was 16% (18/111). In the 5 patients who finally required surgery (4.5%), PuraStat allowed temporary haemostasis and stabilisation.

Conclusions

PuraStat expanded the therapeutic toolbox available for an effective treatment of gastrointestinal bleeding sources. It could be safely applied and administered without complications as a primary or secondary therapy. PuraStat may additionally serve as a bridge to surgery in order to achieve temporary haemostasis in case of refractory severe bleeding, possibly playing a role in preventing immediate emergency surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08589-6.

Therapy- and non-therapy-dependent infectious complications in inflammatory bowel disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are susceptible to infections.

RESULTS

Independently from immunomodulatory therapy, IBD predisposes to infectious complications. Thus, the incidence of Clostridium difficile infection is increased in IBD patients, and a significant proportion of these patients contracts C. difficile infection outside the hospital and without precedent antibiotic use. Cytomegalovirus infection has been reported in cortico- steroid-naive patients with ulcerative colitis, and infectious gastroenteritis has been linked to initiation and exacerbation of IBD. Finally, in Crohn's disease there is a substantial risk for abscess formation, and urinary tract infections occur more frequently than in a non-IBD control population. Apart from the disease process itself, factors that predispose to infectious complications in IBD are malnutrition, advanced age, immunosuppressive medications, leukopenia from immunosuppressive medications, and surgery. However, the main risk for infections is clearly related to the use of immunosuppressive agents such as corticosteroids, azathioprine, methotrexate, cyclosporine, and TNF-blocking biologicals. A wide spectrum of infectious complications has been reported in patients treated with these medications, including viral (e.g. CMV, VZV, EBV), bacterial (e.g. Mycobacteria, Listeria, staphylococci), fungal (e.g. Pneumocystis jiroveci, Aspergillus, Candida, Cryptococcus) and protozoal (Toxoplasma) pathogens. The greatest risks obviously relate to the combined use of immunomodulating agents rather than to individual drugs. The risk of infections is also aggravated by an insufficient immunization status as frequently observed in patients with IBD.

CONCLUSION

Physicians treating patients with IBD must be aware of the risk for infectious complications in these patients as well as of strategies to minimize them.

HIV infection and the intestinal mucosal barrier

HIV infection induces a barrier defect of the intestinal mucosa, which is closely linked to immune activation and CD4 T cell depletion. The HIV-induced barrier defect is initiated in early acute and maintained through chronic infection. In acute infection, increased epithelial permeability is associated with increased epithelial apoptosis possibly caused by perforin-expressing cytotoxic T cells. In chronic infection, mucosal production of inflammatory cytokines is associated with increased epithelial permeability, epithelial apoptosis, and alterations of epithelial tight junctions. In addition to HIV-induced immune-mediated effects, viral proteins have the potential to directly affect epithelial barrier function. After prolonged viral suppression by antiretroviral therapy, there is, at least partial, restoration of the HIV-associated intestinal mucosal barrier defect despite persisting alterations of the mucosal immune system.

Use of microbiological and patient data for choice of empirical antibiotic therapy in acute cholangitis

Background

Ineffective antibiotic therapy increases mortality of acute cholangitis. The choice of antibiotics should reflect local resistance patterns and avoid the overuse of broad-spectrum agents. In this study, we analysed how results of bile and blood cultures and patient data can be used for selection of empirical antibiotic therapy in acute cholangits.

Methods

Pathogen frequencies and susceptibility rates were determined in 423 positive bile duct cultures and 197 corresponding blood cultures obtained from 348 consecutive patients with acute cholangitis. Patient data were retrieved from the medical records. Associations of patient and microbiological data were assessed using the Chi-2 test and multivariate binary logistic regression.

Results

In bile cultures, enterobacterales and enterococci were isolated with equal frequencies of approximately 30% whereas in blood cultures, enterobacterales predominated (56% compared to 21% enterococci). Antibiotic resistance rates of enterobacterales were > 20% for fluorochinolones, cephalosporines and acylureidopenicillins but not for carbapenems (< 2%). The efficacy of empirical therapy was poor with a coverage of bacterial bile and blood culture isolates in 51 and 69%, respectively. By multivariate analysis, predictors for pathogen species, antibiotic susceptibility and expected antibiotic coverage were identified.

Conclusions

In unselected patients treated for acute cholangitis in a large tertiary refferential center, use of carbapenems seems necessary to achieve a high antibiotic coverage. However, by analysis of patient and microbiological data, subgroups for highly effective carbapenem-sparing therapy can be defined. For patients with community-acquired cholangitis without biliary prosthesis who do not need intensive care, piperacillin/tazobactam represents a regimen with an expected excellent antibiotic coverage.

Aeromonas hydrophila beta-hemolysin induces active chloride secretion in colon epithelial cells (HT-29/B6)

The diarrheal mechanisms in Aeromonas enteritis are not completely understood. In this study we investigated the effect of aeromonads and of their secretory products on ion secretion and barrier function of monolayers of human intestinal cells (HT-29/B6). Ion secretion was determined as a short-circuit current (I(SC)) of HT-29/B6 monolayers mounted in Ussing-type chambers. Transepithelial resistance (R(t)) served as a measure of permeability. A diarrheal strain of Aeromonas hydrophila (strain Sb) added to the mucosal side of HT-29/B6 monolayers induced a significant I(SC) (39 +/- 3 microA/cm(2)) and decreased the R(t) to approximately 10% of the initial value. A qualitatively identical response was obtained with sterile supernatant of strain Sb, and Aeromonas supernatant also induced a significant I(SC) in totally stripped human colon. Tracer flux and ion replacement studies revealed the I(SC) to be mainly accounted for by electrogenic Cl(-) secretion. Supernatant applied serosally completely abolished basal I(SC). The supernatant-induced I(SC) was inhibited by the protein kinase C inhibitor chelerythrine, whereas a protein kinase A inhibitor (H8) and a Ca(2+) chelator (BAPTA-AM) had no effect. Physicochemical properties indicated that the supernatant's active compound was an aerolysin-related Aeromonas beta-hemolysin. Accordingly, identical I(SC) and R(t) responses were obtained with Escherichia coli lysates harboring the cloned beta-hemolysin gene from strain SB or the aerA gene encoding for aerolysin. Sequence comparison revealed a 64% homology between aerolysin and the beta-hemolysin cloned from Aeromonas sp. strain Sb. In conclusion, beta-hemolysin secreted by pathogenic aeromonads induces active Cl(-) secretion in the intestinal epithelium, possibly by channel insertion into the apical membrane and by activation of protein kinase C.

Antisecretory effect of loperamide in colon epithelial cells by inhibition of basolateral K+ conductance

BACKGROUND

The mechanism of the antisecretory effect of loperamide was investigated in cultured highly differentiated colon epithelial cells (HT-29/B6).

METHODS

Chloride secretion was stimulated via cAMP by forskolin (FSK, 10(-5) M), via Ca2+ by the muscarinic agonist carbachol (CCh, 10(-4) M), and via protein kinase C by the phorbol ester PMA (5 x 10(-9) M). Stimulated Cl- secretion was quantified as short circuit current (I(SC)) of HT-29/B6 monolayers mounted in Ussing-type chambers.

RESULTS

Loperamide (5 x 10(-5) M) inhibited I(SC) stimulated by FSK, CCh and PMA. The antisecretory action of loperamide was unaffected by preincubation with naloxone (10(-5) M). Furthermore, loperamide strongly inhibited basolateral 86Rb efflux. Like loperamide, the calmodulin antagonist trifluoperazine (10(-4) M) inhibited I(SC) induced by FSK, CCh or PMA. The Ca2+ channel blocker verapamil (5 x 10(-5) M), on the other hand, inhibited only PMA-stimulated I(SC),but had no effect on FSK or CCh-induced I(SC) CONCLUSIONS: Loperamide exerts a direct antisecretory action on chloride secretion of colon epithelial cells independently of the respective stimulatory signal transduction pathway. This antisecretory effect is not mediated by opiate receptors and reflects inhibition of basolateral K+ conductance.

High incidence of cardiac dysfunction and response to antiviral treatment in patients with chronic hepatitis C virus infection

AIMS

Hepatitis C virus (HCV) has been associated with cardiomyopathies. Former anti-HCV therapies employing interferon could have serious side effects in patients with advanced heart failure since interferon may adversely impact upon cardiac function. We, therefore, examined whether the novel, interferon-free and highly virus-selective anti-HCV combination therapy might be applicable even in advanced or end-stage heart failure.

METHODS AND RESULTS

In a retrospective series of HCV-positive patients admitted to our institution with suspected cardiac disease, coronary, valvular or hypertensive heart disease was diagnosed in 70/146 (47.9%). Among the others, 36/76 (47.4%) had myocardial disease: LV (32.9%)/RV (13.2%) hypertrophy, RV dysfunction (13.2%)/dilation (6.6%), severe diastolic dysfunction (7.9%), pulmonary hypertension (22.4%). One critically ill patient listed for heart transplantation (HTX) had previously not tolerated an interferon-based protocol. To still improve her chance of enduring transplant survival, we attempted an interferon-free virus-selective antiviral combination drug protocol under careful monitoring of possible side effects. Regarding clinical status she tolerated this treatment well, with the exception of transient severe hyponatremia requiring substitution. Her NYHA functional class improved from II-IV before to class II immediately after successful complete HCV elimination.

CONCLUSIONS

Whereas prevalence of cardiac dysfunction and potential benefit from antiviral treatment was reported previously, there is lack of data regarding the response of patients with advanced heart failure. Since the highly HCV-selective drugs used above do not eliminate other cardiotropic viruses and have no direct effect on inflammation, massive improvement in such critically ill patients indicates a causal role of HCV in their cardiac failure, and of HCV elimination in their functional recovery.

Distribution and phylogeny of Brachyspira spp. in human intestinal spirochetosis revealed by FISH and 16S rRNA-gene analysis

During six years as German National Consultant Laboratory for Spirochetes we investigated 149 intestinal biopsies from 91 patients, which were histopathologically diagnosed with human intestinal spirochetosis (HIS), using fluorescence in situ hybridization (FISH) combined with 16S rRNA gene PCR and sequencing. Aim of this study was to complement histopathological findings with FISH and PCR for definite diagnosis and species identification of the causative pathogens. HIS is characterized by colonization of the colonic mucosa of the human distal intestinal tract by Brachyspira spp. Microbiological diagnosis of HIS is not performed, because of the fastidious nature and slow growth of Brachyspira spp. in culture. In clinical practice, diagnosis of HIS relies solely on histopathology without differentiation of the spirochetes. We used a previously described FISH probe to detect and identify Brachyspira spp. in histological gut biopsies. FISH allowed rapid visualization and identification of Brachyspira spp. in 77 patients. In most cases, the bright FISH signal already allowed rapid localization of Brachyspira spp. at 400× magnification. By sequencing, 53 cases could be assigned to the B. aalborgi lineage including "B. ibaraki" and "B. hominis", and 23 cases to B. pilosicoli. One case showed mixed colonization. The cases reported here reaffirm all major HIS Brachyspira spp. clusters already described. However, the phylogenetic diversity seems to be even greater than previously reported. In 14 cases, we could not confirm HIS by either FISH or PCR, but found colonization of the epithelium by rods and cocci, indicating misdiagnosis by histopathology. FISH in combination with molecular identification by 16S rRNA gene sequencing has proved to be a valuable addition to histopathology. It provides definite diagnosis of HIS and allows insights into phylogeny and distribution of Brachyspira spp. HIS should be considered as a differential diagnosis in diarrhea of unknown origin, particularly in patients from risk groups (e.g. patients with colonic adenomas, inflammatory polyps, inflammatory bowel disease or HIV infection and in men who have sex with men).

Herpes Simplex Virus Sepsis in a Young Woman with Crohn's Disease

We present the case of a herpes simplex virus-1 [HSV-1] sepsis with severe herpes hepatitis in a young female treated with triple immunosuppressive therapy [adalimumab, azathioprine, prednisolone] for refractory Crohn's disease [CD]. The patient presented with high fever, generalised abdominal tenderness, strongly elevated transaminases, coagulopathy, and pancytopenia. Comprehensive diagnostics including blood HSV-1 polymerase chain reaction [PCR], liver biopsy, and immunohistochemistry revealed the diagnosis of fulminant herpes hepatitis. HSV-1 positivity of cutaneous lesions proved the disseminated nature of the infection. Early treatment with intravenous acyclovir led to a rapid improvement of the patient's condition and resulted in a full recovery of her liver function. This is the first reported case of HSV-sepsis in a patient with CD. Physicians treating inflammatory bowel disease [IBD] patients with combined immunosuppressive therapy should be aware of the possibility of herpes hepatitis, and early empirical antiviral therapy should be considered in immunosuppressed patients presenting with fever and severe anicteric hepatitis.

Trends in the epidemiology of Clostridioides difficile infection in Germany

PURPOSES

Despite reports of a declining incidence over the last decade, Clostridioides difficile infection (CDI) is still considered the most important healthcare-associated causes of diarrhea worldwide. In Germany, several measures have been taken to observe, report, and influence this development. This report aims to analyze the development of hospital coding for CDI in Germany over the last decade and to use it to estimate the public health burden caused by CDI.

METHODS

Reports from the Institute for Hospital Remuneration Systems, German Federal Statistical Office (DESTATIS), the Robert-Koch-Institute (RKI), Saxonian authorities and hospital quality reports during 2010-2021 were examined for CDI coding and assessed in a structured expert consultation. Analysis was performed using 2019 versions of Microsoft Excel® and Microsoft Access®.

RESULTS

Peaks of 32,203 cases with a primary diagnosis (PD) of CDI and 78,648 cases with a secondary diagnosis (SD) of CDI were observed in 2015. The number of cases had decreased to 15,412 PD cases (- 52.1%) and 40,188 SD cases (- 48.9%) by 2021. These results were paralleled by a similar decline in notifiable severe cases. However, average duration of hospitalization of the cases remained constant during this period.

CONCLUSIONS

Hospital coding of CDI and notification to authorities has approximately halved from 2015 to 2021. Potential influential factors include hospital hygiene campaigns, implementation of antibiotic stewardship programs, social distancing due to the COVID-19 pandemic, and a decrease in more pathogenic subtypes of bacteria. Further research is necessary to validate the multiple possible drivers for this development.

Diffuse gastric cancer with peritoneal carcinomatosis can mimic Crohn's disease

In some cases the diagnosis of gastric cancer is difficult and the endoscopic presentation may be misleading. Diffuse type gastric carcinoma with peritoneal metastasis may present primarily with abdominal pain, colonic infiltration and/or diarrhea, thus other differential diagnoses like Crohn's disease (CD) may be considered at first. Therefore intensive diagnostic work-up is important. We report two cases of gastric cancer with ascites due to peritoneal carcinomatosis who were first diagnosed as CD. The patients were hospitalized in different institutions for weight loss, abdominal pain and nausea. The first colonoscopy, upper endoscopy with multiple biopsies and ascites puncture were negative for malignant disease, but macroscopic lesions resembling CD were described. Both patients were released on a prednisolone-based treatment for suspected CD. They presented to our hospital for further evaluation due to persistent symptoms. Neither lower nor upper endoscopy were suggestive of CD and endoscopic ultrasound was suspicious of malignancy in one case. Histology was diagnostic and showed gastric infiltration by a poorly differentiated adenocarcinoma. Diffuse type gastric cancer (gastric linitis plastica) with peritoneal metastasis may mimic certain clinical, endoscopic and CT imaging features of CD. Repeated biopsies and endoscopic investigations are often necessary to confirm a malignant process, especially in case of an inconclusive clinical and endoscopic picture. Endoscopic ultrasound may be useful to evaluate the risk of malignancy in patients with macroscopic suspicion of malignancy and negative biopsies.

Cardiovascular Involvement in Chronic Hepatitis C Virus Infections - Insight from Novel Antiviral Therapies

Whereas statistical association of hepatitis C virus (HCV) infection with cardiomyopathy is long known, establishment of a causal relationship has not been achieved so far. Patients with advanced heart failure (HF) are mostly unable to tolerate interferon (IFN)-based treatment, resulting in limited experience regarding the possible pathogenic role of HCV in this patient group. HCV infection often triggers disease in a broad spectrum of extrahepatic organs, with innate immune and autoimmune pathogenic processes involved. The fact that worldwide more than 70 million patients are chronically infected with HCV illustrates the possible clinical impact arising if cardiomyopathies were induced or aggravated by HCV, resulting in progressive HF or severe arrhythmias. A novel path has been opened to finally resolve the long-standing question of cause-effect relationship between HCV infection and cardiac dysfunction, by the recent development of IFN-free, highly efficient, and well tolerable anti-HCV regimens. The new direct-acting antiviral (DAA) agents are highly virus-specific and lack unspecific side-effects upon cardiac function which have always confounded the interpretation of IFN treatment data. The actual frequency of unexplained HF in chronic HCV infection will be determined from a planned large-scale study. Whereas such patients probably constitute a rather small fraction of all those harboring HCV, they have major clinical relevance. It is not yet known which fraction of these patients will significantly benefit from HCV eradication, but this issue will be addressed now in a prospective study.